i live in the caribbean where we have some rainy days along with the sea and the sun, what works for me is a large white or translucent garbage bag mostly a 39x50 i keep it tied arong the stand so that if rain comes i can easily if possible finish the shoot or get to dry ground without getting my equipment fried.
this has work for me many times.

I shot grizzly bears in a downpour w/ Einstein, in AK. I made a wood housing with vents on bottom, plexiglass window. PVC would work too. I put a stud in the housing and mounted to that. Worked fine, but the fan broke later, probably from getting jarred in transport.